Which of the following types of protein modifications is characterized by the addition of a ubiquitin molecule to a lysine residue on the target protein?

A Phosphorylation
B Ubiquitination ✓
C Acetylation
D Glycosylation

Explanation

Ubiquitination is a type of post-translational modification where a ubiquitin molecule is covalently attached to a lysine residue on the target protein, often marking it for degradation by the proteasome.

Source

Biochemistry textbooks
Protein Metabolism Biochemistry Post-Translational Modifications Medium MEDICAL Confidence: high